Abstract

In the last 2 years we have developed1 a new method for determining insulin biologic activity with the help of the glucose-controlled insulin infusion system (GCIIS). Primarily this closed-loop system infuses insulin. But to prevent hypoglycemia, it can in addition, infuse glucose below a certain blood glucose minimum. This effect is used to reproduce insulin biologic activity. After subcutaneous injection of the insulin to be tested in healthy persons (not in insulin-dependent diabetic subjects), the blood glucose level falls, and this is checked by the counterregulatory glucose delivery from the apparatus. The time and intensity of glucose delivery from the GCIIS reflect the insulin effect, so that each insulin manifests its own particular biologic activity.